Adjustable arming mechanism



June 26, 1951 J. RABlNow 2,558,000

ADJUSTABLE ARMING MECHANISM Filed Oct. 25, 1946 '2 Sheets-Sheet 1 s? ge@ TADDE RAE'IINDW.

June 26, 1951 J. RABlNow 2,558,000

ADJUSTABLE ARMING MECHANISM Filed Oct. 25, 1946 2 SheetsvShee. 2

Syvum/vio@ JAEDE FAenNmw mzwww@ @www Patented June 26, `1951 ADJUSTABLE ARMING MECHANISM Jacob Rabinow, .Washingtom D. C., assigner to the United vStates of America as represented by the Secretary of-War Application October 25, 1946, Serial No. 705,788

Claims. V(Cl. 102-81.2)

(Granted under the act of March s, 1883, as amended April so, 192s; 37o o. G. 757) The invention described herein may be manufactured and used by 'or for the Government for governmental purposes, Without the vpayment to me of any royalty thereon.

The present invention relates to projectile `and bomb fuzes and, more particularly, to delayed arm-ing mechanisms therefor.

Many conventional fuzes are provided with means for `delaying the arming of the fuzes until the projectile or bomb has traveled a predetermined distance. It is a `disadvantage of such arming delay devices, however, that they are not adjustable to any great extent to meet therequirements of varying conditions of use, nor are they able to provide very long arming delays. For the purpose of rendering conventional fuzes adaptable to the varying needs encountered, there is disclosed in my copending application,

. Serial Number 705,787, filed October 25, 1946, a

device for enclosing the nose or" a standard fuze to render the arming mechanism of the fuze inoperable for apredetermined distance or iiight, said device being provided with means to remove the device from the nose of the fuze `in night after a predetermined distance of travel which may be varied over a wide range.

The present invention is an improvement upon the invention disclosed in my said copending application and has for its principal object the Yprovision of a more compact and simplied construction to accomplish the purpose of the devicegof my prior invention.

More particularly, it is an yobject of the present invention to provide an adjustable device adapted to be attached to a standard fuzeto provide an arming Vdelay which eliminates the need for a cover for the fuze nose.

Afm-ther object is to provide a device that will be completely eiTective `in its prevention of premature arming of the fuze, which may be rmly attached to the fuze and, at the same time, Will release itself from the fuze without danger of malfunction.

The accomplishment of the above a-nd other objects will be apparent from the following description of a specific embodiment of the invention shown in the accompanying drawings Vin which: ,Y

Figure 1 isa perspective view of the arming delay device attached to the guard ring of a standard fuze;

Figure 2 is a perspective view of the arming delay device as it is released from lthe fuze;

Figure 3 is a cross-sectional view taken along the. line Y3,-3 @Figure 5;.

Figure 4 is a cross-sectional view taken along' 5, comprises a housing 6 adapted to be securely fastened to the guard ring 3 ,by means of bentup projections l for engaging the lower edge of theguard ring 3 and a rotatable shaftd having a hooked endilfor engaging the upper edge of the Vguard ring 3. A pIfOJ'GCtionpl onthe housing 6, adapted to overlie the guard ring 3 stabilizes the connection l,afforded by projections I and shaft 8.

`When the housing `6 is attached tothe guard ring 3, as described above, it retains VVa pin II 'receivedV through anaperture I`2 in theguard ring in the position shown in vFigure l, whereby the post Il extends between twoo'f the blades of the arming vane 2 and eiectively prevents the vane from rotating. A volute spring lsecured to one end of the pin IA urges the pin away from the guard ring V3 and, when the shaft is turned to a disengaging position, also acts to separate the housing 6 from the guard ringS.

A lever arm Ill is fixed on shaftV 8 and adapted to turn therewith. A spiral spring I5 engaged at one end to the lever armA lli and at the other end to the housing 6 norm-ally urges the lever armlll into the position shown in Figure 2 in which position the shaft ilis rotated sufficiently to disengage its bent end `9 from then upper edge of the guard ring 3Q lWhen the arming delay device 5 is attached to the nose of the fu'ze I, the lever arm Ill is manually rotated to 'the position shown in Figure .1 where its free vend may be received'thr'ough a slot 3E in a cup shaped dial I6 mounted on a rotatable shaft Il whereupon the dial may be rotatedk to retain the end .of the lever arm I4, thus locking the housing 6 on the guard ring 3.

The shaft II on which the dial I6 is mounted is provided with a worm Wheel I8 which is adapted to be driven by va Worm'IS mounted on a rotatable shaft 20. Inasmuch as the dial end of shaft Ilis supported man Lelongatedsl cr t"'2| in the housing 6, its weight will move the worm wheel out of engagement with worm I9. This facilitates the turning of dial IB to a position for retaining the end of lever arm I4 and also for setting the dial for a predetermined night distance as will be explained more fully hereinafter. After the end of lever arm I4 is received within dial IB, the upward force on lever arm I4 produced by the spring I5 lifts the dial I6 and end of shaft I'I to engage the worm wheel I8 with worm I9.

The shaft 2D, and thus the shaft I'I and dial I6 are driven through a gear train consisting of rotatable shafts 22 and 23, worms 25 and 25', and worm wheels 26 and 21, by a vane 28 mounted on the shaft 23. It thus will `be seen that as the vane 28 is rotated by the flow of air during flight of the projectile or bomb, the dial will be slowly returned by means of the speed reduction afforded by the gear train` to the position shown in Figure 2 which releases the lever arm Ill.

As explained above, the release of the lever arm I4 permits the spiral spring I5 to turn the arm and thus the shaft 8 to position shown in Figure 2 so that the hooked end of the shaft no longer engages the guard ring 3. Thereupon, the housing 6 and pin I I are thrown outwardly away from the nose I of the fuze so that the fuze is then able to function in its normal manner.

Taking into account the speed reduction afforded between the vane 28 and dial I6 matT readily be marked and calibrated to show the setting of the dial required to obtain a predetermined arming delay when attached to the fuze.

Due to the characteristics of the load on the vane 28 in relation to the relatively large vane area, there is very little air slip on the vane, whose rotation is therefore essentially a function of air travel rather than air speed. Hence the calibration and setting of the arming mechanism is substantially independent of the speed and is determined by the distance travelled. When my arming device is used on bombs which may be released from an airplane at various speeds, it can still be set for a predetermined distance of travel prior to functioning, which is another advantage of my construction.

In order to render the fuzed projectile safe prior to launching, I employ the customary arming wire, 3I, which is passed through suitable holes in the casing and in pin Il, as shown in Figure 3, and which also obstructs vane 28. lm mediately prior to launching, wire 30 will be withdrawn, and the device will then be ready for operation, as shown in Figure 1.

It will thus be seen that by the device of the present invention it is possible to give a standard fuze arming delay characteristics which may be varied over a wide range as desired. This greatly increases the versatility of standard fuzes and makes it practical to provide fuzes having the greatly varied characteristics required in combat. At the same time, the device is simple in construction and self-releasing from the fuze whereby subsequent operation of the fuze is not interfered with.

Having thus described an embodiment of the invention, it will be apparent that the device may be susceptible of modification by one skilled in the art within the scope of the invention, and all such modifications are intended to be covered in the appended claims.

I claim:

1. A device constructed and arranged to be attached to the guard ring of a fuze to position an arming delay device thereon for a predetermined distance of iiight comprising a projection having a hooked end for engaging one edge of the guard ring of a fuze, a rotatable shaft having a bent end constructed and arranged to be rotated into and out of engagement with the other edge of the guard ring, a spring member for rotating the shaft out of engagement with the guard ring, a lever secured to the shaft for rotating the shaft into engagement with the guard ring, locking means for retaining the lever in position for engaging the shaft with the guard ring, and means responsive solely to distance of air travel for unlocking said locking means during ight.

2. A device constructed and arranged to be attached to the guard ring of a fuze to position an arming delay device thereon for a predetermined distance of flight comprising a projection having a hooked end for engaging one edge of the guard ring of a fuze, a rotatable shaft having a bent end constructed and arranged to be rotated into and out of engagement with the other edge of the guard ring, a spring member for rotating the shaft out of engagement with the guard ring, a lever secured to the shaft for rotating the shaft into engagement with the guard ring, locking means for retaining the lever in position for engaging the shaft with the guard ring, an air vane, and a gear train connecting the air vane to the locking means to unlock same upon a predetermined distance of air travel.

3. A device constructed and arranged to be attached to the guard ring of a fuze to position an arming delay device thereon for a predetermined distance of flight comprising a projection having a hooked end for engaging one edge of the guard ring of a fuze, a rotatable shaft having a bent end constructed and arranged to be rotated into and out of engagement with the other edge of the guard ring, a spring member for rotating the shaft out of engagement with the guard ring, a lever secured to the shaft for rotating the shaft into engagement with the guard ring, a rotatable member for retaining the lever in position for engaging the shaft with the guard ring having a slot for receiving and releasing the lever, an air vane, and a gear train connecting the air vane to the rotatable retaining member for aligning the slot with the lever upon a predetermined distance of air travel.

4. A device constructed and arranged to be attached to the guard ring of a fuze to position an arming delay device thereon for a predetermined distance of night comprising a projection having a hooked end for engaging one edge of the guard ring of a fuze, a rotatable shaft having a bent end constructed and arranged to be rotated into and out of engagement with the other edge of the guard ring, a spring member for rotating the shaft out of engagement with the guard ring, a lever secured to the shaft for rotating the shaft into engagement with the guard ring, a rotatably mounted member having a slot therein .constructed and arranged for retaining the lever in position for engaging the shaft with the guard ring during rotation and for releasing the lever upon sufficient rotation to align the slot with the lever, an air vane, gear means for rotating the rotatably mounted member upon rotation of the air vane, and manually operated for disengaging the rotatably mounted member from the gear means.

5. The combination comprising a projectile fuze, an arming vane rotatably mounted on said fuze, a guard ring on said fuze extending around said arming Vane, means for interlocking said arming vane and guard ring to prevent rotation of the vane relative to the guard ring, a releasable holding member fixed to said interlocking means and engaging the guard ring so as to position the interlocking means in interlocking position, a second air vane rotatably mounted on said holding member, and lightly loaded and oriented so as to rotate as a function of forward air travel, a reducing gear train operatively connected with said second vane, means operable by said gear train to release said holding member after a predetermined rotation of said second vane, and 15 1,643,385

means for forcibly propelling said holding member and its associated elements forcibly away from said guard ring upon release of said holding member, to remove same and said interlocking means from the arming vane.

JACOB RABIN OW.

REFERENCES CITED The following references are of record in the lO-file of this patent:

UNITED STATES PATENTS Number Name Date 676,139 Klumak June 11, 1901 Lafitte Sept. 27, 1927 2,396,245 Butler et al Mar. 12, 1946 

